Possesive pronouns in the accusative
Some verbs take the accusative case, and masculaine articles following These verbs change from der/ein to den/einen
Some prepositions, like ohne and für also need the accusative. Just add -en to the masculine possesive pronoun
Ich bin ohne meinen Freund und ohne meine Schwester hier
I am here without my boyfriend and my sister
Reflexive pronouns in the accusative
Reflexive pronouns go along with reflexive verbs. They always refer to the subject of the sentence
Ich entschuldige mich bei ihr
I am apologising to her
The reflexive pronouns for the first and the second person singular and plural are the same as the personal pronouns in the accusative. Only the third person singular and the plural forms are different: here for both you use the reflexive pronoun sich
Er bedankt sich für das Geschenk
He is giving his thanks for the present
Reflexive pronouns in the dative
Depending on the verb, reflexive pronouns may also be in the dative form.
Er merkt sich den Weg
He is memorising the way
The reflexive pronouns in the dative are the same as in the accusative - only the first and the second person singular are different
Ich mache mir Sorgen
I am worried